In my copending patent application Ser. No. 712,888 filed Mar. 18, 1985, now U.S. Pat. No. 4,664,186, there is set forth a downhole hydraulically actuated pump having a traveling engine valve and a traveling production valve, and a discharge guide assembly connected between the engine and production ends. This unique assembly provides a downhole hydraulically actuated pump having the maximum possible size engine piston and pump plunger. This is so because no external passageways are required in order to provide the engine end with power fluid and to provide the pump end with formation fluid.
The present invention provides improvements in traveling valves for a pump plunger. The improved traveling valve can be used in my above recited, copending patent application, as well as various other types of reciprocating pumps, as for example, the various different downhole pumps referred in this and my copending patent application.
The traveling valve assembly of the present invention is unique in that a connecting rod extends through the pump plunger and forms the valve element. The lower end of the connecting rod extension provides an inlet by which formation fluid is conducted to the production valve assembly. The production plunger provides another part of the valve assembly, and passageways are formed therein which lead to the upper and lower production chambers.
The connecting rod enlargement and production plunger therefore form a lost motion coupling therebetween which move respective to one another in order to open and close the passageways leading to the upper and lower production chambers of the production end. The valve is actuated in response to movement of the connecting rod. This involves inertia, friction, and fluid pressure effected on the valve element and the pump plunger.